Active aerial - A short, active aerial for DXers

10-46 — elektor october 1982 active aerial An active antenna certainly cannot perform miracles. If, for example, we really do want to receive the "Voice of the Andes" on 17790 kHz, we really need a resonant X/2 dipole aerial of about 8 m in length. An active aerial with a rod length of about 1.5 m can only be substituted for the dipole as a physical compromise. The following will show how we arrive at this compromise. active aerial A short, active aerial for DXers half-wave dipoles of up to 95 m in length? Here we have to go into a little more detail. Atmospheric noise is the factor governing the design of receiving aerials. In the case of our half-wave dipole, the atmospheric and industrial noise level is high compared to the noise level of commercially available receivers. Thus, reception quality depends only on the signal itself and the interference received. If the aerial is shortened, the signal-to- noise ratio is initially constant because, although the signal level is red...